DOM

DOM stands for Document Object Model and represents the web page. This allows programs to manipulate the document structure, style, and content.

const listDiv = document.getElementById("list-div");

listDiv.classList.add('new-class');
listDiv.classList.remove('new-class');

BOM

BOM stands for Browser Object Model and represents the browser's window. This allows programs to access browsers functionalities. BOM is like the big container which contains DOM and all other javascript stuff.

// DOM is part of BOM.
window.document.getElementById("list-div");

window.innerHeight
window.location.href
window.alert("some-text");